How do I go about testing a multi asset sensor I m trying to

Question

How do I go about testing a multi asset sensor I m trying to build up a test case that checks to make sure the run requests are all valid but I m having some issues pretty early on Essentially I have a dummy job asset and repo and I m trying to test them with my sensor but get a attempted to init dagster instance but not instance reference was provided However I can t use an ephemeral instance either am I missing something thinking face Code in thread

Zach P · Answer

```class TestMultiAssetSensor def test routes self context = build multi asset sensor context repository def=dummy repo asset keys= AssetKey dummy asset cursor=json dumps dummy asset 202209 abc for run request in db backend upstream sensor context print run request assert False To trigger PDB``` Results in ```dagster core errors DagsterInvariantViolationError Attempted to initialize dagster instance but no instance reference was provided ```

Zach P · Answer

There doesnt seem to be any discussion of dagster instances in the <https docs dagster io concepts partitions schedules sensors sensors testing sensors|sensor testing docs> as far as I can see I tried testing with an ephemeral dagster instance despite the docs warning it would cause an error and it does in fact error laugh cry

Zach P · Answer

Also I m wondering if multi asset sensors are broken for cross repository work I m trying to define one but it fails when calling `context latest materialization records by key ` mentioning that no asset def was given ``` debug error string = created 1665166338 602104000 description Error received from peer unix var folders 78 l6wpx70j495f9hd1qf1gvvr40000gn T tmpe3d1y2j2 file src core lib surface call cc file line 967 grpc message Exception iterating responses AssetKey s cross repo asset were selected but no AssetsDefinition objects supply these keys Make sure all keys are spelled correctly and all AssetsDefinitions are correctly added to the repository grpc status 2 ``` I ve checked the asset key is spelled correctly and it s added to the other repository but not the one the sensor is in I d rather not duplicate assets by adding them to a bunch of repositories For now it looks like I can just use several asset sensors instead of one multi asset sensor but I d prefer to just use one slightly smiling face

Zach P · Answer

I ve also tried using two different methods to pass assets to the sensor ``` multi asset sensor asset selection=AssetSelection keys cross repo asset ``` and ``` multi asset sensor asset keys= AssetKey cross repo asset ``` Neither seem to work disappointed same error Also probably worth noting I m testing with the CLI `dagster sensor preview my Sensor location lt repo my sensor is in gt ` I ve also tried with ` location lt repo my asset is in gt ` but get an error about no sensor being there

sandy · Answer

< jamie> < claire> mind chiming in

claire · Answer

Hi Zach Apologies the asset selection bug is a regression introduced in this latest release and will be resolved in the next release You can use an instance for test to test a multi asset sensor something like ``` multi asset sensor asset keys= AssetKey asset a AssetKey asset b job=the job def a and b sensor context asset events = context latest materialization records by key if all asset events values context advance all cursors return RunRequest run key=context cursor run config= repository def my repo return asset a asset b a and b sensor with instance for test as instance materialize asset a asset b instance=instance ctx = build multi asset sensor context asset keys= AssetKey asset a AssetKey asset b instance=instance repository def=my repo assert list a and b sensor ctx 0 run config == ```

Zach P · Answer

Thanks Claire